The present invention relates to the compound 6-hydroxy-2,6-dimethylheptanal to augment or enhance the flavor and/or aroma of consumable materials, e.g., tobacco, foodstuffs, perfume compositions and perfumed articles.
There has been considerable work performed relating to substances which can be used to impart (or enhance) flavors to (or in) various consumable materials. These substances are used to diminish the use of natural materials, some of which may be in short supply and to provide more uniform properties in the finished product.
Sweet, green, melony, tropical fruit-like, seedy and raspberry-like aromas and tastes are particularly desirable for many uses in foodstuff flavors, particularly natural raspberry flavors. Sweet, green, melony, floral, muguet-like aromas are particularly desirable for use in perfume compositions and perfumed articles such as soaps, detergents, fabric softener compositions, and clothes dryer aroma imparting compositions. Sweet, fruity-melon-like, peach-like, floral and aromatic sweet tobacco-like notes are particularly desirable for smoking tobacco flavoring compositions, particularly where no offnotes are imparted thereto.
Arctander, "Perfume and Flavor Chemicals" 1969, Volume 1 at monograph 1728 discloses the use in perfume compositions, perfumed articles and foodstuff flavors of "Hydroxycitronellal" as follows: ##STR1## Colorless oily or viscous liquid. Sp.Gr.0.93. B.P. 241.degree. C.
Very slightly soluble in water, soluble in alcohol and oils. Poorly soluble in mineral oil and Glycerin or Propylene glycol.
Very slightly soluble in water, soluble in alcohol and oils. Poorly soluble in mineral oil and Glycerin or Propylene glycol.
Sweet-floral, at first delicate and refreshingly mild, but often increasing in odor strength after short olfactory study. The floral notes are mild, light and resemble Lily of the Valley. The tenacity is good, and the odor diffusion increases significantly when the material is properly blended with lower boiling odorants or modifiers.
There is a marked difference in the topnote of this material from different suppliers. Only few manufacturers make a material with a truly uniform, delicately floral odor performance from the very first (initial) note to the terminal notes (dryout, dry-down-notes).
The odor will remain for days, weeks or even longer, but the material on a testing blotter is obviously exposed to air attack and polymerization. A good way--but a very strict one--to evaluate this aldehyde is in lukewarm water. It is sufficiently soluble that it will show water-insoluble impurities strongly enhanced on this test. A very fine grade of Hydroxycitronellal will have almost the same odor on this test as it has on a perfume blotter.
Hydroxycitronellal has a sweet-floral taste, but shows a bitter aftertaste at concentrations higher than 20 ppm, sometimes even much lower than that.
This aldehyde is one of the most frequently used floralizing perfume materials. Originally introduced as a "Muguet" material, it finds its way into almost every type of floral fragrance, and a great many nonfloral ones. Its concentration in perfumes may vary from about 1% (which rarely gives effect unless supported by parallel materials) up to 30 or 40% in straight floral types.
It is almost a "must" in Muguet (at certain price levels) and Peony, Lily, Sweet Pea, Narcisse, Lindenblossom, etc. and it had a monopoly on these types for more than 40 years during which period not one material appeared that could truly replace Hydroxycitronellal. And even after the appearance of one of several very good, perhaps superior materials, the demand for Hydroxycitronellal kept increasing. Endless discussions about its possibly irritating effect on the human skin have hardly died out yet but Hydroxycitronellal has now reached and by-passed the one-million-pounds per year mark in a volume class reserved for comparatively few perfume materials.
For soap perfumes it is customary to use a slightly more "rough" grade of this material. Power is often of paramount interest to the soap manufacturer when it comes to perfuming, and the very pure grade materials with delicate odors often fail to yield the desirable power in a soap.
High-grade Hydroxycitronellal is used sparingly in flavor compositions as a floralizer in many types of flavors: Berry complexes, Citrus, Violet, Cherry, etc. and in general, a discrete touch of floral note in a flavor tend to give impression of "richness" or "body" which are highly desirable virtues. In some cases, a complete Muguet base is added to a flavor--fruit, Mint, etc.--to lend this "rounding-off" effect. The amounts needed are mere traces.
Hydroxycitronellal enters these flavor types at the concentration equal to 0.3 to 15 ppm in the finished product.
Prod.: (many methods) e.g. from Myrcene, via Myrcene dihydrochloride to Dichloro di-methyloctene. This is converted to Chloro di-hydrogeranyl acetate (andneryl acetate) with Sodium Acetate in Benzene in presence of Triethylamine. The acetates are saponified with Calcium hydroxide to yield Hydroxycitronellol, from which the aldehyde is prepared by oxidation.
Older methods start Citronellal via the Bisulfite which is hydrated to yield Hydroxycitronellal.
G.R.A.S. F.E.M.A. No. 2583."
Hydroxycitronellal differs from 6-hydroxy-2,6-dimethylheptanal not only in structure but in the unexpected differences in organoleptic properties insofar as perfumery, foodstuff flavoring and smoking tobacco flavoring is concerned.
Thus, the 6-hydroxy-2,6-dimethylheptanal of our invention has unexpected, unobvious, advantageous organoleptic properties insofar as quality and substantivity of aroma and flavor with respect to hydroxycitronellal which is disclosed by Arctander.
United Kingdom Pat. specification No. 1,330,848 discloses the preparation of hydroxycitronellal (called "7-hydroxy-dihydrocitronellal") from citronellal itself by means of the reaction of citronellal with a secondary amine at a temperature below ambient temperature; and then transforming the thus--obtained derivative by treatment in aqueous acid medium at a temperature in the range of from -30.degree. C. to 0.degree. C. into a citronellal-immonium ion; and then hydrating the citronellal-immonium ion at ambient temperature; and then hydrolyzing the thus formed 7-hydroxy-dihydrocitronellal immonium ion by strong base into 7-hydroxy-dihydrocitronellal keeping the temperature within limits such that the salt which is formed during the hydrolysis reaction remains in solution all operations taking place in the liquid phase.
German Offenlengungsschrift No. 2,441,030 assigned to the Gividuan Corporation discloses a process for preparing Lyral having the structure: ##STR2## reacting a compound having the structure: ##STR3## with morpholine to form an aminal having the formula: ##STR4## and then hydrating the double bond of the aminal to form the hydroxy aminal and finally decomposing the hydroxy aminal to form the compound having the structure: ##STR5##
The compounds produced according to the prior art references are different in kind from the compound 6-hydroxy-2,6-dimethylheptanal produced in the instant case, 6-hydroxy-2,6-dimethylheptanal being different in chemical structure and in organoleptic properties from any of the relevant compounds of the prior art or any of the compounds formed by the processes which are relevant in the prior art.